A multi-function environmental logger that combines air velocity, air/ambient temperature, contact temperature (via K or J thermocouple), relative humidity, and light-level measurement in one handheld unit, with an optional adapter available to add sound-level readings. Like REED's other SD-series meters, it logs directly to an SD card at adjustable intervals and can dump the data to Excel without dedicated software. A dual 4-digit backlit display, tripod/kickstand mounting, and a choice of AA battery or AC power make it suited to extended unattended site surveys.